Door closer with oil brake



1945- G. N. PETT ERSEN DOOR CLOSER WITH ,OIL BRAKE "Fil'ed Nov. 25,--1941 construction; isv avoided.

I Patented Feb. 13, 1945 A. noon CLOSER wrrn OmBRAKE Gunnar Nimrodi Pctter'scn', Oslo, Norway; vested in the Alien Property Custodian Application. November 25, 1941, Serial No. 420,411

In Norway February 1, 1940 4 Claims. (01216 -55) invention relates to door closers having an oil; brake arranged radially to the axis of rotation of the door andv in which a helical spring acting between the cylinder and thepisto'n of the oil brake: causes the: closingzby intermediation of a. cam: member. v

Door closers or this kind have the advantage that they may beaccommodated as a whole in thedoor so that they are not visible, but onthe other hand they have the disadvantage of not'being very reliable since-the cam member which in the case of known'doorclosers is in the formof an eccentric rotating with the door and actuated by the piston of the stationary oil brake acts with such a short arm that the door closer does not-afford the required closing moment without a very great spring force.

According to the present invention this disadvantage is. overcome by the fact that the oil brake is fixed onthe pivot of the door so as to partake in the rotation movement of the door, and the cam member is formed 'by a stationary guiding pathfor the outer end. of the brake.

Hereby it becomes possibleto let the closing force act witha greater arm. According to a mrther: feature of the invention this may be further utilized for keeping the door safely in place in the closed position by giving the guiding path such a form that by the transmission of. the spring force provided by the c'ammin-g; action it aifoxzds-a; resistance. against rotation of the door from closed position. With an outer guiding path this is possible without difliculty, whereas when using an eccentric it would be very difiicult becausea steep cam surface. would be required at the smallest radius of the eccentric so that by an increase: of the viscosity of the cil due to a decrease in temperature the door might easily be stuck. Thus, by this feature of the invention the disadvantage that the dooris often blown open, which is: frequently encountered with theprior Another reason for lack of reliability of door closers of this kind is that the ball valves usually employed which control the passage of the oil through the piston do not operate safely under all conditions since it may happen that the ball may stick due to the variations in the consistency of the oil which occur by changes in temperature, According-to a further feature of the invention this disadvantage is avoided by the fact that the piston rod of the oil brake forms the valve element for closing and opening the passage of the oil through the piston by being adapted to perform a, short movement with respect to the latter which movementis limited by two stops of which that at which the pistonhead is entrained during closingv closes said passage". 1

Still another disadvantage in oil filled. door closersadapted for being accommodated in the floor'isthat the oil may migrate out of the casing and soil the floor. According to a further feature of the invention this is avoided by providing. the oil casing with a double cover containing-a chamber to receive oil which migrates from the oil chamber.

Other features of r the invention will appear from the following specification connection with the drawing which shows a preferred embodiment.

. n the drawing: v

, Figure 1 is a. horizontal section through the door closer in the position corresponding to closed position of the door and Figure 2 is a vertical axial section showing the door closer inthe position corresponding to open positionof the door.

The door closer shown is designed for use with a door adapted to be opened in both directions andis therefore symmetric with respeot'to the plane of the door opening. Its casing consists of an oil casing I closed. by a cover 2'. The cover 2- is fastened by screws (not shown) to a flange 3 with a packing 4 therebetween. Besides; at the upper side of the cover 2. there is' a chamber 5 covered by a. second cover 6 for receiving oil which migratesirom-the casing l-.-

In thecasing l and the cover 2 respectively are mounted collar ball bearings 1, 8 for the pivot 9 p which is provided with a packing ill for the cover 2. The upper extremity of pivot 9 is shown as formed with a. polygonal portion II for extension into a matched fitting on the door so as to rotate with the same. I

The pivot 9 carries the oil brake with the cylinder l2 thereof shown as cast in one piece With the pivot. The cylinder t2v has a telescopic connecticn; with apiston member l3 which near its outer end carries. a. fixed pivot [4 for a roller l5 and which comprises a skirt-portion l6 at the outside of the cylinder l2 and a central piston rod I! which penetrates the base of the cylinder l2 and acts on the piston head l8.

Around the cylinder l2 and the skirt l6 there the skirt portion l6 of the piston member for ad:

justing the spring pressure;

When the door and thereby the oil brake are turned the roller 45 runs on the roller path 22 of the inside wall of the casing l. Over a section of the roller path 22 rangingfrom closed position to an opening angle of about 90 the roller path 22 has a decreasing distance from the axis of rotation so that during the opening movement of the door the piston member I3 is pushed inward and the spring is is compressed, whereas during closing the spring I9 pushes the member I3 outward so that the oil brake and thereby the door are turned back to the position shown in Figure 1. At the point where the roller is situated in closed position as shown in Figure 1 the roller path is shown forming a point so that by the camming action between the roller and the roller path the spring l9 affords a certain resistance against turning of the door from this position in order that the door shall not be opened by wind force. However, it is possible also to provide a recess in the roller path at this point so that a still more marked resistance .for the roller results.

As shown in Figure 2 the pivot 14 for the roller l has a downward extension so as to form a projection guided in a groove 23 at the outside of a flange 24' projecting from the bottom of the oil casing. Hereby it is ensured that the piston member l3 will follow its path when the door is closed by hand with greater velocity than that which corresponds to the operation of the door closer.

As indicated by 25 in Figure 1 the curvature of the guiding path is changed-at an opening angle of about 90 so that the distance from the axis of rotation again increases, whereby it will be possible to let the door remain in fully opened position without being closed by itself, For this.

for preventing. the door closer from passing beyond the position 25. For this purpose a screw may be used which is inserted through a suitable threaded hole in the cover 2 and has sulficient length for acting as a stop for the member l3. Preferably the screw ought to have a support at the lower end which has been indicated by bores 26 in the bottom of the casing in Figure 1. For uses for which the stop is not desired the'threaded hole in the cover may be closed by a short screw acting as a plug.

In the embodiment shown the piston rod ll acts as a valve member for opening and closing the oil passage 21 through the piston head 18, the piston rod having at the end a head 28 which abuts against a valve seat 29 on the piston head. The opening of the valve is caused by the inward movement of the member I3, the piston rod being able to move a short distance with respect to the piston head until it abuts against the same with a stop 30 which does not close the passage 21. The cylinder chamber communicates with the oil chamber outside through a duct 3| which passes through the piston rod l1 and may be throttled more or less with a screw 32 provided in the member l3, according to the consistency of the oil.

The oil brake operates in the following manner: When the door is opened and the member i3 is pushed inward the valve 28, 29 is opened and the stop 30 entrains the piston l8 inward so that the cylinder chamber is filled with oil rangement employed a very safe operation of the oil brake is obtained.

A door closer according to the invention may be carried out in many other ways than that shown. For example, instead of using a radially movable piston and a cylinder fixed on the pivot it is well possible to use the inverse arrangement, etc.

I claim:

1. A door closer comprising an oil brake arranged radially to the axis of rotation of the door and a helical spring acting between the cylinder and piston of the oil brake and causing the closing movement of the door with the intermediation of a cam member, characterized by the fact that the oil brake is fixed on the door pivot so as to take part in the rotational movement'of the door and that the cam member is formed by a fixed guiding path for the outer end of the oil brake.

2. A door closer according to claim 1; characterized by the fact that the guiding path is of such a form that by the transmission of the spring force due to the camming action it affords a resistance against turning of the door from closed position.

. 3.. A door closer according to claim 1, characterized by the fact that near the point of the guiding path corresponding to full opening of the door the curvature of the guiding path changes so that at the point corresponding'to full opening of the door it does not afiord any component of force in the closing direction.

4. A door closer according to claim 1, characterized by the fact that inside and in parallel relation to the guiding path which causes the automatic closing there is provided a flange which, in co-operation with a projection of the oil brake provided between the flange and the guiding path, prevents the door from being closed without the oil brake being entrained.

GUNNAR NIMROD PETTERSEN. 

